Penicillin allergies are the most reported drug allergy. However, 90 per cent who report a penicillin allergy are negative on testing.

Our own experts in Infectious Diseases were taught “facts” that we now know are incorrect.

In the lead up to Antibiotic Awareness Week (18-24 November), Epworth VMO Associate Professor Jason Trubiano, an Infectious Diseases specialist, says clinicians are reteaching doctors and pharmacists about penicillin.

So, what are some of these myths?

MYTH: Penicillin allergy lasts forever.

FACT: It doesn’t & the vast majority have very low risk penicillin allergies.

MYTH: Those who are allergic can’t take any of the penicillin drugs.

FACT: The penicillin class is a very big family of drugs. You may be allergic to plain penicillin, but you can take a cousin of that.

MYTH: 10% of people may be allergic to the entire penicillin family

FACT: Less than 2% of people are allergic to the entire penicillin family.

The miscomprehension around allergy is due to an accumulation of factors. “Our mothers are not always right – they may have told you as a kid that you had an allergy, but it could be a mistaken identity. Symptoms may have been from the infection or another reason, not the penicillin. After 10 years, 80 per cent of people outgrow their allergy.” - Jason Trubiano, Infectious Disease Specialist, Epworth HealthCare.

After all these years, the penicillin class is still a first choice drug.

The whole class of penicillin is fantastic and a first choice drug. These are the drugs we want to use in frequent flyer patients with chronic illnesses.

Being more aware of antibiotic use has become more important as antibiotic resistance grows and there are few new drugs coming into the market. ”It’s a bit of a grim story - In my grandfather’s lifetime, we have wasted and misused antibiotics. We had the great discovery of penicillin in the 40s and more discoveries up to the 80s and then it drops off. We are not blessed with new antibiotics every week, like we are with new chemotherapy drugs. We have to find ways to protect the antibiotic drugs we have and use the most targeted.”

By 2050, people will be surviving longer with great drugs but dying of infections. We haven’t thought enough about supportive care over the long term.

Dr Ben Teh, antimicrobial stewardship clinician at Epworth says there can be worse outcomes with alternative antibiotics. Alternative antibiotics may be less effective, more toxic, or contribute to antibiotic resistance.

We can do better with antibiotic use, it is a challenge for us, as antibiotics are quite limited and bugs are more resistant. We have to use antibiotics with great care.

Accurate allergy history taking can help clarify a patient’s risk of allergic reaction, and identify those who would benefit from further investigation by an expert.

15 November 2019